The juxtaposition of presumptive neural plate and epidermis forms a signaling center responsible for the stereotypic pattern of dorsal neurons in the neural plate (including lateral primary neurons in amphibians and fish), roofplate, neural crest cells and cranial placodes (Baker and Bronner-Fraser, 2001; Moury and Jacobson, 1990; Selleck and Bronner-Fraser, 1995). In addition, signals from thi...

O N E of the most important means of studying the phenomena of induction and determination during the development of the central nervous system consists in microsurgical operations of different kinds on the neural plate of Urodela. Hence it is important to have the neural plate mapped with regard to the prospective significance of its different parts, the 'materielle Anlagen' of Mangold (1937)....

Cranial placodes are thickenings in the ectoderm that give rise to sensory organs and peripheral ganglia of the vertebrate head. At gastrula and neurula stages, placodal precursors are intermingled in the neural plate border with future neural and neural crest cells. Here, we show that the epigenetic modifier, DNA methyl transferase (DNMT) 3A, expressed in the neural plate border region, influe...

Planar-cell-polarity (PCP) signalling is necessary for initiation of neural tube closure in higher vertebrates. In mice with PCP gene mutations, a broad embryonic midline prevents the onset of neurulation through wide spacing of the neural folds. In order to evaluate the role of convergent extension in this defect, we vitally labelled the midline of loop-tail (Lp) embryos mutant for the PCP gen...

Automatic vehicle license plate recognition system plays an important role in Intelligent Transportation System. Even though many license plate recognition methods have been proposed in the past, further scope for improvement still exists. This paper has proposed a new approach to license plate recognition system based Harris corner detection algorithm. In this paper connected component analysi...

We have identified Xenopus Brain Factor 2 (XBF-2) as a potent neuralizing activity in an expression cloning screen. In ectodermal explants, XBF-2 converts cells from an epidermal to a neural fate. Such explants contain neurons with distinct axonal profiles and express both anterior and posterior central nervous system (CNS) markers. In striking contrast to X-ngnR-1a or X-NeuroD, ectopic express...

Fate-map studies have provided important information in relation to the regional topology of brain areas in different vertebrate species. Moreover, these studies have demonstrated that the distribution of presumptive territories in neural plate and neural tube are highly conserved in vertebrates. The aim of this review is to re-examine and correlate the distribution of presumptive neuroepitheli...

Neural-tube closure is a critical step of embryogenesis, and its failure causes serious birth defects. Coordination of two morphogenetic processes--convergent extension and neural-plate apical constriction--ensures the complete closure of the neural tube. We now provide evidence that planar cell polarity (PCP) signaling directly links these two processes. In the bending neural plates, we find t...

We describe the expression pattern of cSix3, a chick homologue of the murine Six3. cSix3 transcripts are expressed from presomitic stages in the most anterior portion of the neural plate. As the neural tube folds and the optic vesicles evaginate, cSix3 is expressed in the optic vesicle and the rostroventral forebrain. At later stages, cSix3 is found in most of the structures derived from the an...

In vertebrates, canonical Wnt signaling controls posterior neural cell lineage specification. Although Wnt signaling to the neural plate is sufficient for posterior identity, the source and timing of this activity remain uncertain. Furthermore, crucial molecular targets of this activity have not been defined. Here, we identify the endogenous Wnt activity and its role in controlling an essential...